Influence of Age, Sex, and Body Habitus on the Mean QRS Electrical Axis in Childhood and Adolescence

Abstract

The "mean QRS electrical axis" has been defined by Ziegler (1951) as the average direction in which the excitatory process spreads throughout the ventricular myocardium. This mean axis or vector in the frontal plane may be calculated from the standard limb leads and used as an index of cardiac abnormality. In biometrics the term "deviation" is usually used to indicate the departure of a measurement from an established normal value. Thus in electrocardiography right or left axis deviation denotes departure of the electrical forces from the normal toward one or other side of the body. Accurate interpretation of such deviation is dependent upon well-established normal standards, and several authorities (Johnston, 1961;Ezra, 1961;Milnor, 1962) Ashman, 1937;Epstein, 1948;Gros, Gordon, and Miller, 1951;Yu, Joos, and Katsampes, 1951;Veasy and Adams, 1952; Sodi-Pallares et al., 1958a), and many have contained relatively few cases in later childhood and adolescence. Ziegler (1951) considered that his own data on the mean QRS axis merely acted as a "satisfactory nucleus for further study and revision."This investigation, which is part of a larger study of electrocardiograms in normal children and adolescents (Walker and Rose, 1961; Walker and Wershing, in preparation) was thus designed to test statistically the hypotheses of previous writers and to present normal standards related to age, sex, and body habitus from an adequate number of subjects between the ages of 6 months and 20 years. SUBJECTS AND METHODSThe records of 2082 patients who attended the Denver Rheumatic Fever Diagnostic Service during the years 1957 to 1961 were reviewed. Despite the special nature of this clinic, a complete history was taken and a thorough physical examination performed, each patient being examined by two or more experienced piediatric cardiologists on the medical centre faculty. Laboratory studies included urine examination, himatocrit, white blood cell count, differential count, sedimentation rate (Wintrobe), C-reactive protein, and serum mucoprotein tyrosine. A 14-lead electrocardiogram (standard 12 leads plus V3R and V7) was recorded on a standard direct writing Cambridge instrument at 25 mm./sec. paper speed, with a calibration of 1 mV= 10 mm. The majority of the earlier patients had either cardiac fluoroscopy or routine radiograms with barium swallow. More recently, if the history was negative and the murmur typically innocent, this examination was omitted in order to avoid unnecessary radiation. As a result of the evaluation of the 2082 case records, 1199 patients were excluded for one of the following reasons: the history or presence of recent illness (as evidenced by physical findings, raised sedimentation rate, white blood count, or abnormalities in the urine), diagnosis or suspicion of rheumatic fever (past or present), the diagnosis of congenital or acquired organic heart disease or the suspicion of such abnormality. The remaining 883 patients were thus regarded as being normal and were included in this study.

The Evolution of the Neonatal QRS Axis during the First Four Weeks of Life

“…In contrast to previous studies performed in older children, and findings in adults, we observed a significant sex difference in the QRS axis [17,18] with a less pronounced right-shifted axis for girls. However, we did not find any significant association between QRS axis and body size in our cohort, contrary to findings in adults.…”

“…Abnormalities in the QRS axis, in particular, the socalled left axis deviation (LAD, 0 to −90°) in children has long been a focus of attention, because of the association with multiple forms of cardiac pathology, including tricuspid atresia, atrioventricular septal defects, and Wolff-Parkinson-White syndrome [1,8,9]. The incidence of LAD in the pediatric population has not been well established, but previous estimates range from 1 to 2% [12,18]. The reported rate of heart disease among children with LAD on their ECG varies between studies.…”

Left ventricular mass by 12-lead electrocardiogram in healthy subjects: comparison to cardiac magnetic resonance imaging

“…The ability to estimate left ventricular mass (LVM) from the standard 12-lead electrocardiogram (ECG) is limited. Demographic and anthropometric variables such as age, sex, height, weight and body fat all contribute to variability of the 12-lead ECG (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). Thus, heterogeneity with respect to these determinants may explain the limited accuracy of the 12lead ECG in estimating LVM.…”

Το Ηλεκτροκαρδιογραφημα Της Μαθητικης Ηλικιας. Προσδιορισμο Των Φυσιολογικων Δεικτων Των Βασικων Παραμετρων Του Ηλεκτροκαρδιογραφηματος Και Εξακριβωση Του Ειδους Και Της Συχνοτητας Των Παθολογικων Ευρηματων Σε 2.362 Μαθητες Και Μαθητριες Ηλικιας 7-17

“…Τό σύνδρομο LGL 235 χαρακτηρίζεται στό ηλεκτροκαρδιογράφημα άπό φυσιο λογικό σύμπλεγμα QRS χωρίς κόμβωση, του όποιου ή διάρκεια δέν ξεπερνά τά 80 msec καί άπό βράχυνση τού διαστήματος Ρ -R, ή όποια παραμένει σταθερή μέ τήν πάροδο της ηλικίας. 107 , 331 Κλινικά, χαρακτηρίζεται άπό παροξυσμικές ύπερκοιλιακές ταχυκαρδίες, πού οφείλονται σέ έπανείσοδο στην περιοχή τού κόμ βου.ι 50 'Υπάρχουν πολλές θεωρίες γιά τόν μηχανισμό του συνδρόμου LGL : Ή θεω ρία της κομβικής παρακάμψεως 251 διά μέσου της πρόσθιας ένδοκολπικής δέσμης, τής δέσμης του James ή των λειτουργικών παρακαμπτηρίων ινών εντός του κόμ βου, ή θεωρία τής έπιταχυνομένης άγωγης 275 443 'Αντίστοιχα, ή αριστερή εκτροπή του άξονα του κοιλιογραφήματος 52 . 106 είναι σπάνια στά παιδιά, 383 .…”

“…106 είναι σπάνια στά παιδιά, 383 . 443 ένώ ό μέσος άξο νας μετατοπίζεται βαθμιαία προς τ' αριστερά 183 παράλληλα μέ τήν ηλικία, 158 .…”